Answer: This was because the experiment showed that a substance could emit radiation even while it was not exposed to light.
Answer:
The time required to melt the frost is 3.25 hours.
Explanation:
The time required to melt the frost dependes on the latent heat of the frost and the amount of heat it is transfered by convection to the air .
The heat transferred per unit area can be expressed as:
being hc the convective heat transfer coefficient (2 Wm^-2K^-1) and ΔT the difference of temperature (20-0=20 °C or K).
If we take 1 m^2 of ice, with 2 mm of thickness, we have this volume
The mass of the frost can be estimated as
Then, the amount of heat needed to melt this surface (1 m²) of frost is
The time needed to melt the frost can be calculated as
Answer:
Three orbitals
Explanation:
The electronic configuration of carbon is given as follows;
1s²2s²2p²
Therefore, out of the six electrons of the carbon atoms, 4 fill the 1s and 2s orbitals with 2 electrons each, while the two remaining electrons are situated in the 2p orbital, with the electrons in the 2p orbital will remain unpaired such that they will have similar quantum numbers in accordance with Pauli exclusion principle.
Answer: The correct option is 1.
Explanation: Endothermic reactions are the reactions in which heat is provided to break down the reactant molecules.
In option 1:
The stronger intermolecular forces between the particles in solid molecule are broken down to convert into gaseous form. Hence, some energy in the form of heat is provided to move them far apart. Therefore, it is considered as an endothermic reaction.
In option 2, 3 and 4:
All the other processes involves the formation of bonds and thus there is no need to provide any energy.
Answer:
I think the answer is boiling
